Former New England Patriots tight end Aaron Hernandez touches his lip as Alexander Bradley testifies during Hernandez's double murder trial in Suffolk Superior Court, Monday, March 20, 2017, in Boston. Hernandez is on trial for the July 2012 killings of Daniel de Abreu and Safiro Furtado who he encountered in a Boston nightclub. The former NFL football player is already serving a life sentence in the 2013 killing of semi-professional football player Odin Lloyd. (AP Photo/Steven Senne, Pool)

(AP) – Aaron Hernandez’s death in prison has been officially ruled a suicide. That determination comes from the district attorney’s office in Worcester County, Massachusetts.

Authorities say investigators found three handwritten notes next to a Bible inside the maximum-security prison cell where the ex-NFL star was found hanging early Wednesday.

They said Thursday there was no sign of a struggle and that the former New England Patriots tight end was alone. Investigators say Hernandez, who was serving a life sentence for a 2013 murder, blocked access to his cell from the inside by jamming cardboard into the door tracks.

They say he was locked in his cell at about 8 p.m. and that no one entered until a guard saw him just after 3 a.m. and forced his way in to try to save Hernandez.